I was involved in the 2nd turnaround on the B744 / KE812, which originally departed on time at 1930 local. I got a call at 2315, from a rather upset Korean Airlines rep, to advise that it doing an air return, and was back on Bay 51 at 0135.
The pax weren't disembarked (poor devils), while the official bag scrutiny was performed (some dudes just checking out several bags), and the airline reps organised a new crew, fuel and extra catering.
I do believe from my conversation with the Korean rep, that it was made to return as "punishment" for breaching the security protocols, but I guess they stoically had to accept the decision, as it was their stuff up.
It has cost them a fortune, as I believe they are up for $A150000 curfew penalty/dispensation fee + 82000 litres of extra fuel + new crew + catering + etc, etc.
I left the a/c at 0335 and I think it departed at approx 0400.
Confucious say "Bugger!!"